in repect of quantities of oil and gas, possible reserves are those reserves which are not yet proven or probable but which, on all the available evidence and taking into account technical and economic factors, have a better than 10 per cent chance of being produced

Those reserves which cannot at present be regarded as probable and are estimated to have a significant but less than 50% chance of recovery.

Those reserves which at present cannot be regarded as 'probable' but are estimated to have a significant but less than 50% chance of being technically and economically producible.

Additional reserves that are less certain to be recovered than probable reserves. It is unlikely that the actual remaining quantities recovered will exceed the sum of the estimated proved plus probable reserves. There should be at least a 10% probability that the actual quantities recovered will equal or exceed the sum of the estimated proved plus probable plus possible reserves.

Estimated oil and/or gas reserves in an unexplored area, based on preliminary survey results (geologic surveys, etc.).